Whilst there is still no clinically recognised cure for vitiligo, there are certainly plenty of examples of people who have either partially or totally re-pigmented, using a variety of different treatments. And yet the precise mechanism involved in skin re-pigmentation is still not known. No one even knows if there is in fact just one single process going on inside the skin, or a variety of different ones. For example, was the mechanism involved in my re-pigmentation using a nutritional approach the same as that of a patient who has had success with UVb therapy alone? I would think almost certainly not.
Successful UV treatment typically results in follicular re-pigmentation. If I understand what I have read correctly, narrow band-UVb therapy – when successful - is believed to work through two separate processes within the skin. Firstly, UVb radiation activates the stem cells located in the “niche” at the bulge region of the hair follicle. And secondly, it causes keratinocytes - another type of skin cell within the epidermis - to produce the hormone α-MSH which, in turn, binds to receptors on the melanocyte and activates melanin production. Colour returns to the skin surrounding the follicles in freckles at first and then gradually migrates outwards and joins up to produce larger “islands” of normal pigmentation.
The well-documented fact that re-pigmentation tends to occur mainly in those areas of skin where there are still pigmented hairs points to the important role played by hair follicles. But surely this can’t be the whole story because skin (and hair) can, and does, re-pigment in areas where the hairs had previously lost their colour. And skin can, and does, re-pigment in areas where there is little or no hair growth at all. For example, most of my white eyelashes returned to their normal colour, as did areas of the hair on my head that had turned white. And the entire undersides of my arms where there is no visible hair whatsoever (as well as the outer portions where there is some hair growth) also re-pigmented completely, despite having been totally white for decades. However, those parts of my hands and feet that are completely hairless have proved much slower to respond and are still – just like the sum of knowledge on the mechanics of re-pigmentation itself – a little patchy!
My name is Caroline.